1. Field of the Invention
This invention relates to the drive axle of a vehicle, specifically to the use of axle torque to enhance the performance and suspension of a vehicle.
2. Background of the Invention
When a vehicle accelerates forward weight is transferred towards the rear of the vehicle. This weight transfer causes additional weight to be placed on the rear of the vehicle compressing the suspension. Similarly weight is transferred off the front suspension lightening the load on the front axle. For many years this was not a problem but as the power output of engines and the traction of tires increased the weight transfer became so great in some high performance vehicles as to cause insufficient weigh to remain on the front axle, and thus the front tires, resulting in a lack of steering control.
Inventors have addressed this problem in many ways, but all with the same aim; to limit the amount of vertical front suspension or wheel travel. U.S. Pat. No. 4,353,571 to Anderson acknowledges this. This invention allows a motorcycle to be ridden with the front wheel not in contact with the road surface but a ‘wheele bar’ attached behind the rear wheel and used as a stabilizer. It should be noted, however, that there is no steering control for the rider using the above mentioned device.
Another problems associated with the power gains of modern engines is the driving axle causing a twisting or ‘winding up’ effect on a typical leaf spring type suspension. As early as 1965 solutions were being sought and U.S. Pat. No. 3,191,711 from this date is an early attempt. It should perhaps be noted that this invention uses the principle of my invention, that is, axle torque, but used to lower the rear of the vehicle for improved traction of the rear tires. While effectively solving the problem of axle ‘wind up’ it was later discovered that raising the car beneficially altered the moment of the center of gravity for improved traction. U.S. Pat. Nos. 4,098,523 and 5,354,092 are other examples of typical solution to the problem of axle ‘wind up’ but do nothing to address the problem of the lack of steering control mentioned above.
A chassis design proposed by Jones, U.S. Pat. No. 4,988,120 addresses both problems by limiting the amount the front suspension is allowed to travel with the use of ‘wheelie bars’, mentioned above, U.S. Pat. No. 4,353,571, Anderson. However if the weight transfer of acceleration has sufficient inertia, weight can actually be transferred from the rear wheels to the wheelie bar causing a lack of traction for the rear tires.
Another problem, particularly for motorcycles, is created by improvements to the brakes. This problem is the opposite of the rearward weight transfer described above. During braking weight is transferred forward. If the braking force is powerful enough the rear wheel(s) can lose contact with the road with a resulting loss in braking efficiency and control. The solution provided by my invention uses the reaction to engine torque, or wheel mass inertia on braking, coupled to a simple linkage or other means, to reverse the effects of weight transfer on the vehicle's suspension.